Game starts at the last sub-level of the fourth level. You are Adam and you need to pass the Skeletor's robots in order to get to the chamber where Mer-Man is hiding.

You have at your disposal three spells in your magic panel (key M): one spell that can heal you, one spell that invokes TriSword (magic swords that follow you & attack your enemies) & one spell that will negate the magic barrier and allow you to pass it.

You also have one book(map) in your inventory (Key I) that will show you how to go through the narrow labyrinth path in the Mer-Man's chamber without falling in the swamp-looking water below.

Technical info

The Mer-Man's Lair is the original level from the Secret Of The Sword set of levels, but it did had one technical difference- it featured level geometry with baked textures & lights. At that time I was experimenting with Acknex A6 engine abilities and baking of textures & lights into one single map allowed for much faster rendering.

The downside was very blurry looking textures as you will notice once you load the level :) Post-processing effects & few shaders that are present are added by me to improve enjoyment, they were not a part of the original level.